Vintage (Howard) Hughes Tool Co Drill Bit 7-1/2 J From my late grandfather's collection. Markings as follows: 7 1/2 J 52751-1 PROP HUGHES TOOL CO SER NO 16071 Just a guess, but might be manufactured on May 27, 1951 10-1/4" tall 7-1/2" wide business end 4-1/4" base Approx 40lbs